Brian Chirchir shows slab samples of plastic fused soil during the 2016 JKUAT Tech Expo on November 4, 2016. The slab can be used in construction of fish ponds and dams. PHOTO BY LABAN ROBERT.

Farmers with porous soils, but want to construct fish ponds can do so using a student-innovated cheap plastic-sand fused material that does not allow for water to escape.

Clay soil allows for minimum water seepage. Sand soil particles do not hold water. Only farmers in regions with clay or polythene linings for holding can engage in fish rearing. 

But Jomo Kenyatta University of Agriculture and Technology (JKUAT) students have come up with the plastic fused soil slab, which is made from locally available materials.

The material is made from sand particles mixed with melted waste plastics, which form an inert, hard and non-porous slab.

The slab is laid on the floor and against the walls of the fish pond irrespective of the soil type.

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Brian Chirchir, a JKUAT Civil Engineering Student, said besides reducing pollution with the plastic wastes, the innovation aims at boosting food security by helping those who cannot afford expensive polythene linings.

“Polythene linings are good, but their lifespan is limited to less than five years. The 15mm slab can last for more than 10 years. My group (four students) is offering pollution solution. Poor soil farmers can also have a chance to engage in fish production despite their soil,” he said.

The plastic waste in melted to form a dense semi solid substance, which is then mixed with sand soil before cooling to form the mass impermeable substance.

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Apart from application in the fish ponds, the slab can be used in construction of domestic water reservoirs as and dams.

During construction of dams, clay slabs of 75mm are required for holding the water. But he same work can be done by the 15mm thick slab, Chirchir said.

Prisons officer helps farmers set up integrated backyard fishponds: 

Whilst polythene lining may cost more than Sh200 per square metre, the plastic fused soil slab of the same size costs Sh20.

Chirchir can be reached on +254708665203.